PEI treatment plant simplifies batch sludge handling with VEPAS polymer system

DATE POSTED: July 30, 2019

Vepas System

A compact, non-mechanical polymer mixing system is making sludge dewatering easier and more efficient for the North Rustico Wastewater Treatment Facility (WWRF) in Prince Edward Island. Since its commissioning, in May 2014, the plant has relied on a Venturi Emulsified Liquid Polymer Activation System (VEPAS) to inject and activate polymer in a single pass with no mechanical agitation needed. 

The one-step, venturi-based VEPAS eliminates many of the components used in mechanical polymer systems, such as mixers and aging tanks. These components not only increase system size, but also require operator attention for maintenance and cleaning. VEPAS also enables operators to easily change the rate of polymer flow—a feature that is particularly important for the North Rustico WWRF, which processes highly variable sludge in batches for dewatering in Geotube® containers. 

Allan Nisbet, Operator, at the North Rustico WWRF says that waste sludge from the plant is pumped to a storage tank and dewatered in batches about every six to eight weeks. Since the composition of the sludge varies greatly from batch to batch, Allan always tests the sludge to determine the proper polymer dose rate before pumping sludge to the Geotube® dewatering containers. 

“The VEPAS is very simple to operate and provides precise control of the polymer dose, which helps maximize dewatering and reduce our polymer use,” Allan says. “Our system is equipped with an HMI operating panel where we can easily change and monitor the polymer dose rate.” Once the batch is complete, Allan says it takes only about an hour to completely disassemble, clean and reassemble all components – the polymer pump, lines and injector. 

“We’ve had great communication and support from Bishop Water, not only during plant commissioning, but on an ongoing basis,” Allan says. “The team recently suggested a new polymer for the dewatering process after reviewing one of our sludge tests. This new polymer should work better with our variable sludge and improve dewatering.” 

The VEPAS and Geotube® dewatering has enabled the North Rustico WWRF to become self-sufficient for sludge handling. Solids are dewatered, composted and distributed at the site as landscaping material, eliminating the need for hauling it away for treatment and disposal. 

Read more about how composted solids are used at North Rustico WWRF.

Learn more about the VEPAS 

Contact us to discuss a VEPAS for your treatment plant. 

Polymer Injection System Simplifies Mixing while Maximizing Dewatering

DATE POSTED: April 25, 2018

Bishop Water’s polymer injection system – the VEPAS – is specially designed and customizable to each project

Chemical costs can play a significant part in sludge handling, but a specialized polymer system form Bishop Water Technologies can help reduce chemical costs and dramatically simplify polymer mixing and handling. The Venturi Emulsified Polymer Activation System (VEPAS) is designed to fully activate liquid polymer emulsions in a single pass without the use of mechanical agitation or mix tanks.

This easy-to-operate, reliable polymer injection system, which functions with very few moving parts, not only saves space, but also helps minimize the damage to polymer molecules. Damaged polymer is less effective and requires a greater quantity to achieve the desired dewatering results. Once activated, the polymer can be added immediately to the sludge flow flocking line or stored in a batch tank for future use.

The VEPAS can be used in mobile applications such as Geotube® emergency sludge dewatering, or for full-scale Geotube® dewatering applications at wastewater lagoons or water treatment plants. It can be adapted easily into the activated sludge process simply by introducing a polymer feed line into the sludge feed line. The system will run automatically and adjust the amount of polymer added to the sludge based on the flow.


Read More about different types and sizes of the VEPAS.

Read our case study to see how Bishop Water’s solids management solution has been used as part of a long-term dewatering solution at the North Rustico Wastewater Treatment Plant.

Contact Us about your project.

mobile trailer

Mobile Dewatering Trailer